There is an increased demand for low cost printing of books and the like which can performed by a user as opposed to a commercial printer. Techniques have been developed for binding of sheets to form a book having characteristics that are similar to commercially bound books. One such technique, described in U.S. Pat. No. 5,052,873, the contents of which are hereby fully incorporated herein by reference, uses a binder strip having a thermally activated adhesive. The binder strip functions to bind the sheets together in the form of a book, with the strip being located along the spine of the bound book. Although books bound using this technique have become popular, it usually necessary to print descriptive information regarding the book, such as author, title and the like on the front and back covers of the book rather than on the spine (binder strip) of the book. Thus, for example, when the book is placed on a shelf, it is necessary to remove the book from the book read the descriptive information printed on the covers. Another approach is to print an adhesive-backed label using a label printing machine and applying the label to the spine (binder strip) of the bound book. A primary shortcoming of this approach is that the book is unprofessional in appearance.
It would be desirable to be able to print descriptive information on the binder strip before the book is bound. However, the physical characteristics of most binder strips are such that printing is very difficult. For example, binder strips frequently have a roughly textured surface which is not conducive to printing. In addition, binder strips are relatively thick due to the adhesive backing making printing difficult. This adhesive backing also causes many binder strips to curl to some extent around the primary axis of the strip further adding to the difficulty of printing. Also, it is necessary to very precisely locate the print on binder strip in order to eliminate any skew which can be visually detected between the printed matter and the edge of the strip. This is very difficult since the human eye is capable of detecting a very small amount of skew under these circumstances where the printed matter is positioned on a thin elongated strip. Further, the conventional printing inks are not always capable of adequately covering many binder strips. By way of example, if light colored print, such as white print, is to be placed on a dark colored binder strip, the underlying strip has a tendency to show through the printed matter. Adding to the difficulty is the fact that the actual binding process usually requires application of heat to the biding strip, with such high heat having adverse effects on some types of print.
There is a need for a printer having a print head mechanism which is capable of printing on binder strips so that bound books can be easily provided having an professional appearance. A printer in accordance with the present invention is capable of printing binder strips notwithstanding the above-noted and other difficulties associated with carrying out such printing. These and other advantages of the present invention will become apparent to those skilled in the art upon a reading of the following DETAILED DESCRIPTION OF THE INVENTION together with the drawings.